![]() ![]() Spoilage has been reported in a range of beverage products, including various fruit juices and blended juice products, carbonated fruit drinks, iced tea and fruit flavoured water, as well as in canned tomatoes. acidiphilus can also produce tainting compounds and have been isolated from spoiled products occasionally. The species most commonly associated with spoilage is A. Numbers as low as 10 4 CFU/ml have been found in spoiled samples and growth can occur at ambient temperatures. Large populations of Alicyclobacillus are not always necessary before detectable spoilage occurs. ![]() The most commonly detected tainting compound is guaiacol, but halophenols such as 2,6-dibromophenol have also been identified in spoiled drinks. Unfortunately, some isolates produce powerful tainting compounds as secondary metabolites, and these impart a characteristic taste and odour, often described as antiseptic, medicinal or phenolic. Spoilage is not usually obvious because no gas is produced, and may go undetected until the product reaches the market and consumer complaints are received. But where it does occur, it can be a serious and costly problem for drinks manufacturers. Although Alicyclobacillus species seem to be quite common in fruit products, probably as a result of soil contamination, their presence does not always lead to spoilage. The ability of these bacteria to grow under the acid conditions in fruit juices means that they may multiply in the finished packaged product. It is thought that the 'heat shock' of pasteurisation may in fact promote spore germination. The spores are relatively heat-resistant and are capable of surviving the pasteurisation treatments typically applied to fruit juices and other shelf-stable beverages. They are aerobic and reported to grow over a very wide range of temperatures (4 - 70 oC) and pH values (0.5 - 6.5), although isolates from spoiled fruit drinks do not usually grow at very low temperatures or under extreme acid conditions. Alicyclobacillus' PhenotypeĪlicyclobacillus spp., are Gram-positive, non-pathogenic, thermophilic and acidophilic spore-forming bacteria found in acid hot springs and in soil. About 20 species of Alicylcobacillus have now been identified. But further genetic investigation revealed that these bacteria were in fact quite different from other Bacillus sp., and in 1992 the genus Alicyclobacillus was proposed as a suitable home for them. These thermophilic acidophilic species were initially classified as Bacillus coagulans, but similar isolates from volcanic springs in the USA were classified as a new species and named Bacillus acidocaldarius.Ī number of other species were later identified, including the isolate from the spoiled apple juice in Germany, subsequently named Bacillus acidoterrestris. Spore-forming bacteria able to grow at high temperatures and low pH values were first isolated from thermal springs in Japan in 1967. A number of methods based on traditional and rapid technologies have been developed to meet this need. The availability of sensitive detection tests is therefore important for screening ingredients and finished products to ensure that they are free from Alicyclobacillus spp. These bacteria can be a serious problem because some strains are capable of producing a distinctive and powerful chemical taint in fruit-based drinks and they are difficult to control once present in the processing environment. Since then, similar spoilage has been widely reported all over the world. This was the first recorded incident of fruit juice spoilage by bacteria now known as Alicyclobacillus. Until comparatively recently, only yeasts, moulds and a few lactic acid bacteria were considered capable of spoiling drinks based on, or containing fruit juices because of their low pH.īut in 1984, large-scale spoilage of ambient-stable aseptically packed apple juice by heat resistant bacteria was reported in Germany. are unusual and potentially important spoilage bacteria for the beverage industry. are also known as Thermophilic Acidophilic Bacteria (TAB)ĭownload the Ultrapure Type 1 Water Interview nowĪlicyclobacillus spp. IFU Method for testing for Alicyclobacillus was revised in May 2019 (See Revised IFU Method).Can cause off flavours in beverages, spoilage may not be obvious as no gas is produced.Aerobically grows over wide range of temperature and pH.Alicyclobacillus is a cause of microbial spoilage in fruit juices.Gram +ve, non-pathogenic, thermophilic and acidophilic spore forming bacteria. ![]()
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